To break a dog from being interested in a rattlesnake, they used defanged live snakes (dead things smell different than live things) and a shock collar set on maximum. If the dog showed any interest in the snake when walked downwind of it, it was zapped. HARD.
While it may seem cruel to some people, it was less cruel than having a dog bitten by a snake miles or possibly hours from any vet service. It worked VERY well, and while I took my dogs thru the course every year, after the first year they never were zapped again. They learned their lesson and remembered.
The same could be done with livestock, but the problem is that the owners of the offending dogs usually just don't care. It'd be impossible to do the training if you didn't own the dog.
